Compare Claude Opus 4.8 and Claude Sonnet 5: Analytical Rigor vs Modern Agent Speed
Claude Opus 4.8 vs Claude Sonnet 5: which should I use?
Claude Sonnet 5 brings faster execution and lower pricing ($2.00/$10.00 per million tokens) for autonomous coding agents, while Claude Opus 4.8 offers 500K context and deep analytical reasoning ($5.00/$25.00 per million tokens). Verified 2026-09-07.
Verified 2026-09-07
Where can you find price, speed, and task evidence for Claude Opus 4.8 and Claude Sonnet 5?
Which tasks fit Claude Opus 4.8 and Claude Sonnet 5?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Opus 4.8 | Claude Sonnet 5 |
|---|---|---|
| Best fit | Complex, multi-step tasks where Fable 5’s premium isn’t justified. | Production workloads that need near-Opus quality with better speed and cost. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Opus 4.8 and Claude Sonnet 5?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Opus 4.8 | Claude Sonnet 5 |
|---|---|---|
| Coding Agent / task | $0.15 (modeled) | $0.06 (modeled) (winner) |
| Input / output rate | $5.00 / $25.00 per M | $2.00 / $10.00 per M |
How fast are Claude Opus 4.8 and Claude Sonnet 5?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Opus 4.8 | Claude Sonnet 5 |
|---|---|---|
| Measured throughput | 58 tokens/s | Unavailable |
| Time to first token | 470 ms | Unavailable |
How compatible are Claude Opus 4.8 and Claude Sonnet 5 with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Opus 4.8 | Claude Sonnet 5 |
|---|---|---|
| OpenAI SDK | Not drop-in | Not drop-in |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
| Streaming | SSE (Anthropic content-block events) | SSE (Anthropic content-block events) |
What are the privacy and retention policies for Claude Opus 4.8 and Claude Sonnet 5?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Opus 4.8 | Claude Sonnet 5 |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Unavailable |
How much effort does it take to migrate between Claude Opus 4.8 and Claude Sonnet 5?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Opus 4.8 | Claude Sonnet 5 |
|---|---|---|
| Move Claude Opus 4.8 → Claude Sonnet 5 | drop-in; 0 breaking parameter differences | Target: Claude Sonnet 5 |
| Move Claude Sonnet 5 → Claude Opus 4.8 | Source: Claude Sonnet 5 | drop-in; 0 breaking parameter differences |
| Why | Same provider; only the model identifier changes. | Same provider; only the model identifier changes. |
Batch 52 · exact pair decision and evidence contributions. Surface verification: 2026-09-01. These three boards are server-rendered from frozen fixtures; assumptions and unavailable joins are not observations.
Exact pair boundary: requested models are claude-opus-4-8 and claude-sonnet-5. A broad provider, pricing, task, or rate-limit verdict is out of scope.
Opus-4.8-to-Sonnet-5 contract delta register
Frozen Batch 52 fixture board. Formula / decision rule: parity = exact host + parameter + accepted value + response field + reserve; unknown => probe before migration Boundary: This register proves pair-specific replacement readiness; model pages retain standalone contract facts.
| Frozen fixture / field ID | Joined fields and evidence | Output | State |
|---|---|---|---|
batch52-claude-opus-4-8-vs-claude-sonnet-5-m1-r1plain text | host=api.anthropic.com; old=claude-opus-4-8; new=claude-sonnet-5; response=content blocks; effort=matched | parity=conditional until exact response-field probe | CONDITIONAL — probe response contract |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m1-r2extended reasoning | old/new=exact; control=thinking budget; effort=declared; response=thinking+answer fields | do not silently drop or rename the thinking control | CONDITIONAL — control probe required |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m1-r3strict JSON | response_format/schema=declared; schema hash=required; old/new support=Unresolved | schema parity=Unavailable; preserve old route | UNAVAILABLE — schema support join |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m1-r4parallel tools | tools=parallel; tool schema hash=declared; call IDs=required; side_effects=read-only | parity requires per-call order, IDs, and schema validation | CONDITIONAL — replay probe |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m1-r5800K context | input=800K; output reserve=declared; exact context ceilings=host/version join | admission=Unavailable until both ceilings and accounting join | UNAVAILABLE — context reserve |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m1-r6provider-gateway | host=gateway; requested=Opus/Sonnet; effective ID=Unknown; parameter map=host-local | gateway cannot inherit direct Anthropic parity | FAIL CLOSED — host identity |
Provenance: Batch 52 claude-opus-4-8-vs-claude-sonnet-5, first-party evidence, surface verification date 2026-09-01. Anthropic Claude model documentation. Missing joins fail closed.
Replacement-evidence crosswalk
Frozen Batch 52 fixture board. Formula / decision rule: decision weight applies only when source + task + version + effort/tools + denominator match; asymmetric coverage => no aggregate verdict Boundary: Launch evidence and provider claims do not substitute for a workload-owned replacement observation.
| Frozen fixture / field ID | Joined fields and evidence | Output | State |
|---|---|---|---|
batch52-claude-opus-4-8-vs-claude-sonnet-5-m2-r1shared coding evaluation | source=first-party/independent; task=coding; version=same required; effort/tools=same; n=required; Opus/Sonnet=missing | comparable delta=Unavailable | UNAVAILABLE — values/denominator missing |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m2-r2shared agent evaluation | source=paired run required; task=agent; version/settings/tools=exact; side_effects=contained | weight only after both effective responses validate | CONDITIONAL — paired run required |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m2-r3mismatched benchmark version | Opus=revA; Sonnet=revB; effort=unknown; sample=not aligned | exclude from aggregate replacement verdict | NOT COMPARABLE — revision mismatch |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m2-r4provider-only score | source=Anthropic claim; model=Sonnet 5; Opus row=missing; judge/denominator=Unavailable | retain as provider claim; not replacement evidence | UNAVAILABLE — one-sided claim |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m2-r5local one-prompt result | source=local; prompt hash=one; tools=none; n=1; production workload=not representative | diagnostic only; cannot promote replacement | INSUFFICIENT — sample floor not met |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m2-r6missing-side fixture | Opus observation=present; Sonnet observation=missing; prompt/config hash=not paired | no aggregate verdict and keep rollback target | HOLD — asymmetric coverage |
Provenance: Batch 52 claude-opus-4-8-vs-claude-sonnet-5, first-party evidence, surface verification date 2026-09-01. Anthropic Claude model documentation. Missing joins fail closed.
Canary promotion and rollback board
Frozen Batch 52 fixture board. Formula / decision rule: promote = quality floor + p95 SLO + token/error/side-effect gates + sample floor; otherwise hold or rollback Boundary: Only workload-owned observations count for release; third-party benchmark scores cannot promote traffic.
| Frozen fixture / field ID | Joined fields and evidence | Output | State |
|---|---|---|---|
batch52-claude-opus-4-8-vs-claude-sonnet-5-m3-r11% shadow | cohort=shadow-1; prompt/tool parity=required; traffic=1%; side_effects=none; sample_floor=declared | decision=Hold until baseline and candidate hashes join | HOLD — shadow evidence pending |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m3-r25% read-only | cohort=readonly-5; tools=read; quality_floor=declared; p95=measured required; errors=tracked | promote only if all gates pass over sample floor | CONDITIONAL — measured gate |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m3-r310% tool-use | cohort=tools-10; tool schema parity=required; side_effects=contained; token_delta=measured required | rollback on schema/error/side-effect regression | GATE — tool containment |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m3-r425% coding | cohort=coding-25; prompt hash=paired; tests=required; p95=measured; sample_floor=declared | decision=Unavailable until test and latency observations join | UNAVAILABLE — cohort evidence missing |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m3-r550% mixed | cohort=mixed-50; quality floor=critical cohorts; error/side_effect state=tracked; rollback=Opus | hold unless every critical cohort passes | HOLD — critical cohort gate |
batch52-claude-opus-4-8-vs-claude-sonnet-5-m3-r6regression | cohort=any; quality/tool/schema/error/side_effect gate=fail; rollback target=Opus 4.8 alive | rollback immediately; investigate before resuming | ROLLBACK — gate failure |
Provenance: Batch 52 claude-opus-4-8-vs-claude-sonnet-5, first-party evidence, surface verification date 2026-09-01. Anthropic Claude model documentation. Missing joins fail closed.
Method and limitations: calculations use only the displayed deterministic rule and visibly labeled assumptions. Missing provider, host, alias, version, effort, tool, modality, benchmark, workload, rate-period, or date joins fail closed. Run the claude-opus-4-8-vs-claude-sonnet-5 Batch 52 scenario →
Batch 65 · exact-pair decision contributions · verified 2026-09-07
Exact pair boundary: Anthropic; same provider, generational shift, analytical depth vs agentic coding flagship, and pricing must join. Requested models are claude-opus-4-8 and claude-sonnet-5. Provider, rate, pricing, and task pages remain fact owners.
Token pricing and 2.5x enterprise migration expenditure board
Frozen Batch 65 scenario board. Formula / deterministic rule: monthly_spend = calls * ((in_tokens * rate_in + out_tokens * rate_out) / 1M) Boundary: Owns base token tariff comparisons and upgrade budgeting.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch65-claude-opus-4-8-vs-claude-sonnet-5-m1-r110K agentic coding tasks | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=10K agentic coding tasks; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 5 spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10K agentic coding tasks is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m1-r250K automated pull request reviews | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=50K automated pull request reviews; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 5 spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50K automated pull request reviews is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m1-r3100K customer workflow orchestrations | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=100K customer workflow orchestrations; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 5 spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 100K customer workflow orchestrations is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m1-r4prompt caching active (90% read discount both) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=prompt caching active (90% read discount both); workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 5 spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — prompt caching active (90% read discount both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m1-r5batch processing active (50% both) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=batch processing active (50% both); workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 5 spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — batch processing active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m1-r6unresolved pricing currency | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=unresolved pricing currency; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 5 spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved pricing currency has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic API pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.
Context window scaling (500K vs 200K) and ingestion gate
Frozen Batch 65 scenario board. Formula / deterministic rule: eligible = (context <= 200K ? Both : (context <= 500K ? Opus : Excluded)) Boundary: Owns context scaling and capability gating for large inputs.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch65-claude-opus-4-8-vs-claude-sonnet-5-m2-r1isolated function edit (10K tokens) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=isolated function edit (10K tokens); context size; Opus 4.8 eligible; Sonnet 5 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — isolated function edit (10K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m2-r2component test suite (75K tokens) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=component test suite (75K tokens); context size; Opus 4.8 eligible; Sonnet 5 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — component test suite (75K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m2-r3full microservice code (200K boundary) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=full microservice code (200K boundary); context size; Opus 4.8 eligible; Sonnet 5 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — full microservice code (200K boundary) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m2-r4monolithic system codebase (450K tokens) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=monolithic system codebase (450K tokens); context size; Opus 4.8 eligible; Sonnet 5 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — monolithic system codebase (450K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m2-r5500K full context saturation test | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=500K full context saturation test; context size; Opus 4.8 eligible; Sonnet 5 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 500K full context saturation test is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m2-r6unsupported archive payload format | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=unsupported archive payload format; context size; Opus 4.8 eligible; Sonnet 5 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unsupported archive payload format has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic Claude model documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Agent tool calling reliability and developer productivity ROI
Frozen Batch 65 scenario board. Formula / deterministic rule: roi = developer_time_saved - ((in_tokens * rate_in + out_tokens * rate_out) / 1M) Boundary: Owns developer productivity modeling and tool loop execution ROI.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch65-claude-opus-4-8-vs-claude-sonnet-5-m3-r1single-file bug patch (Sonnet optimal) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=single-file bug patch (Sonnet optimal); development task; Sonnet 5 fit; Opus 4.8 fit; cost comparison; time saved value; productivity winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — single-file bug patch (Sonnet optimal) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m3-r2multi-file refactoring loop (Sonnet optimal) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=multi-file refactoring loop (Sonnet optimal); development task; Sonnet 5 fit; Opus 4.8 fit; cost comparison; time saved value; productivity winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — multi-file refactoring loop (Sonnet optimal) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m3-r3deep mathematical theorem proof (Opus optimal) | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=deep mathematical theorem proof (Opus optimal); development task; Sonnet 5 fit; Opus 4.8 fit; cost comparison; time saved value; productivity winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — deep mathematical theorem proof (Opus optimal) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m3-r4complex architectural compliance audit | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=complex architectural compliance audit; development task; Sonnet 5 fit; Opus 4.8 fit; cost comparison; time saved value; productivity winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — complex architectural compliance audit is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m3-r5agent loop runaway circuit breaker | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=agent loop runaway circuit breaker; development task; Sonnet 5 fit; Opus 4.8 fit; cost comparison; time saved value; productivity winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — agent loop runaway circuit breaker is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch65-claude-opus-4-8-vs-claude-sonnet-5-m3-r6unresolved developer hourly rate | pair=claude-opus-4-8 vs claude-sonnet-5; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-5; scenario=unresolved developer hourly rate; development task; Sonnet 5 fit; Opus 4.8 fit; cost comparison; time saved value; productivity winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved developer hourly rate has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic Claude documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Method and limitations: formulas are deterministic; observed and assumed inputs are labeled; no missing provider, host, account, region, realm, alias, snapshot, revision, weight, artifact, control, tool, modality, workload, rate-period, timestamp, or result is transferred. Run the claude-opus-4-8-vs-claude-sonnet-5 Batch 65 scenario →
How do Claude Opus 4.8 and Claude Sonnet 5 compare on specs?
| Claude Opus 4.8 | Claude Sonnet 5 | |
|---|---|---|
| Price (input) | $5.00/M | $2.00/M ✓ |
| Price (output) | $25.00/M | $10.00/M ✓ |
| Blended price | $10.00/M | $4.00/M ✓ |
| Context window | 500,000 tokens | 500,000 tokens |
| Max output | 64,000 tokens | 64,000 tokens |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2026-04 | 2026-06 |
| Speed | 58 t/s | Not measured |
How much do Claude Opus 4.8 and Claude Sonnet 5 cost at scale?
| Tokens / month | Claude Opus 4.8 | Claude Sonnet 5 | Delta |
|---|---|---|---|
| 1,000,000 | $10.00 | $4.00 | $6.00 (2.5×) |
| 10,000,000 | $100.00 | $40.00 | $60.00 (2.5×) |
| 100,000,000 | $1000.00 | $400.00 | $600.00 (2.5×) |
Choose Claude Opus 4.8 if…
- ✓Elite coding and multi-step reasoning
- ✓Strong instruction following on ambiguous prompts
- ✓Extended-thinking mode
- ✓Complex, multi-step tasks where Fable 5’s premium isn’t justified.
Choose Claude Sonnet 5 if…
- ✓Frontier intelligence at Sonnet economics
- ✓Fast interactive coding performance
- ✓Reliable structured output and extended thinking
- ✓Production workloads that need near-Opus quality with better speed and cost.
Run this exact matchup right now
Send the same prompt to Claude Opus 4.8 and Claude Sonnet 5 side by side and see the outputs yourself.
Try Claude Opus 4.8 vs Claude Sonnet 5 FreeWhat are common questions about Claude Opus 4.8 and Claude Sonnet 5?
Is Claude Opus 4.8 cheaper than Claude Sonnet 5?
Claude Sonnet 5 is cheaper, at $4.00 per million blended tokens vs $10.00 for Claude Opus 4.8.
Which has the bigger context window, Claude Opus 4.8 or Claude Sonnet 5?
Both models support 500,000 tokens of context.
Can Claude Opus 4.8 replace Claude Sonnet 5 for coding?
Both are viable for coding. Elite coding and multi-step reasoning (Claude Opus 4.8) vs Frontier intelligence at Sonnet economics (Claude Sonnet 5) — pick based on which strength matters more for your workload.
Neither of these? See Claude Opus 4.8 alternatives or Claude Sonnet 5 alternatives.
What related comparisons help choose between Claude Opus 4.8 and Claude Sonnet 5?
Claude Opus 4.8 pricingClaude Sonnet 5 pricingvs Claude Opus 4vs DeepSeek V4 Provs Gemini 3.1 Provs Gemini 3.7 FlashPremium model tests
Pricing verified 2026-06-07. Specs verified 2026-08-14.